Toxicology Commons^™

Recent Developments In Detection And Therapeutic Approaches For Antibiotic-Resistant Bacterial Infections, Kavya Moorthy, Kai-Chih Chang, Hsueh-Hui Yang, Wen-Min Su, Cheng-Kang Chiang, Zhiqin Yuan

Journal of Food and Drug Analysis

Owing to the widespread emergence and proliferation of antibiotic-resistant bacteria, the therapeutic benefits of antibiotics have been reduced. In addition, the ongoing evolution of multidrug-resistant pathogens poses a challenge for the scientific community to develop sensitive analytical methods and innovative antimicrobial agents for the detection and treatment of drug-resistant bacterial infections. In this review, we have described the antibiotic resistance mechanisms that occur in bacteria and summarized the recent developments in detection strategies for monitoring drug resistance using different diagnostic methods in three aspects, including electrostatic attraction, chemical reaction, and probe-free analysis. Additionally, to understand the effective inhibition of drug-resistant …

Effect Of Lifestyle-Based Lipid Lowering Interventions On The Relationship Between Circulating Levels Of Per-And Polyfluoroalkyl Substances And Serum Cholesterol, Stephanie Morgan, M. Abdul Mottaleb, Maria P. Kraemer, Debra K. Moser, Jessica Worley, Andrew J. Morris, Michael C. Petriello

UK CARES Faculty Publications

Exposure to certain per-and polyfluoroalkyl substances (PFAS) has been shown to be positively associated with total and/or low-density lipoprotein cholesterol. Examining this association in lipid lowering interventions may provide additional evidence linking PFAS to cardiovascular risk. We examined the relationship of 6 PFAS with cholesterol in a 6-month lifestyle-based intervention. We quantitated PFAS in 350 individuals at baseline and post intervention and examined associations of PFAS with cholesterol before and after intervention. Food frequency questionnaires and GIS analyses were used to investigate PFAS hotspots and possible exposure routes. Cholesterol significantly decreased following intervention and in parallel, PFOS, PFOA, PFHxS, and …

Comparing The Toxicant Responses And Culturing Characteristics Of Long-Term Laboratory-Reared And Field Populations Of Ceriodaphnia Dubia, Victoria Rose Lydy

Student Theses and Dissertations

Ceriodaphnia dubia is an EPA-recommended organism used in regulatory toxicity testing of surface waters and commercial chemicals. They are often cultured for extended periods in the laboratory with little knowledge of how it impacts subsequent generations. This thesis investigated if C. dubia cultured for an extended period were representative of three recently-collected field populations by comparing their culturing characteristics and sensitivities to toxicants. Comparative chronic toxicity tests with sodium chloride, the neonicotinoid insecticide thiamethoxam, and mixtures of the two toxicants measured differences in sensitivities among the laboratory and field cultures, specifically in the variability of responses. For culturing characteristics, the …

The Effects Of Salinity And Acetaminophen On The Aquatic Snail Physa Acuta, Michelle Sackey-Ansah, Megan Mackey, Daniel Elias, Jason Doll, Alyssa Brookhart

Journal of the South Carolina Academy of Science

Pharmaceuticals are increasingly detected in water bodies, and their presence can negatively impact aquatic organisms. This effect can be amplified when combined with increasing salinity in freshwater ecosystems. Acetaminophen is a widely used analgesic that is commonly found in river, streams, and waters where it is discharged directly. Therefore, organisms present in these locations (e.g., insects, snails, amphibians, and fish) are likely to be affected by acetaminophen. In this study, we determined the effects of elevated salinity (0.68 g/L), acetaminophen (500 µg/L) and combined elevated salinity (0.68 g/L) and acetaminophen (500 µg/L), on the growth, reproduction, and movement of the …

Characterization Of Antiviral Immunity, Host Virus Interactions, And Toxicity Of Agrochemical Residues In The Western Honey Bee, Christopher Fellows

LSU Doctoral Dissertations

Honey bee colonies have perished at an alarming rate for over 15 years. Among the multitude of threats to bee health, virus infections and agrochemical exposure appear to be major drivers of colony loss. As virus infection is among the most damaging influences on bee health, we first investigated a putative target for antiviral immunity, termed K_ATP channels. We previously demonstrated that pharmacologically activating K_ATP channels induces the production of reactive oxygen species and increases survival during infection with Israeli Acute Paralysis Virus. Here, we demonstrate that K_ATP modulation and ROS induction reduce virus replication and enhance …

Phase 1a Clinical Study For Q-Griffithsin Intranasal Spray For Prevention Of Coronavirus, Megan Bezold, Kenneth Palmer, Nobuyuki Matoba, Elizabeth Cash

Posters-at-the-Capitol

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible virus that causes acute respiratory disease with possible long-term complications, known as coronavirus disease 2019 (COVID-19). Griffithsin (GRFT; including the oxidation-resistant variant Q-GRFT used in this study) is an algal carbohydrate-binding protein exhibiting antiviral effects against many enveloped viruses, including all major variants of SARS- CoV-2 reported to date. Q-GRFT has been recombinantly manufactured in Nicotiana benthamiana plants, thoroughly purified, and formulated as an intranasal spray designed to be developed as a non-vaccine broad-spectrum prophylactic product for acute use. This is the first-in-human, randomized, double-blind, placebo-controlled study. The …

Mancozeb Exposure Results In Oxidative Stress And Disruption Of Mitochondrial Complexes Iii & Iv In Transformed Human Colon Cells, Amanda Dhaneshwar

Theses and Dissertations

The ethylene bisdithiocarbamate pesticides, a subclass of the dithiocarbamate pesticides, are broad spectrum organometallic fungicides used on a variety of crops. The fungicide Mancozeb is comprised of an ethylene bisdithiocarbamate backbone complexed to the metals manganese and zinc. Ingestion of food containing pesticide residue and occupational exposure are common routes of Mancozeb exposure. Previous work demonstrated that Mancozeb exposure to HT-29 colon cancer cells resulted in cytotoxicity, apoptosis, and disruption of mitochondrial complex I, II, and V activity. The current study investigated the effect of Mancozeb exposure on mitochondrial complex III and IV activity and oxidative stress parameters in the …

Cytotoxicity Of Copper (Ii) Octanoate On Mouse Hippocampal Astrocytes, Ali A. Shohatee

Theses and Dissertations

Copper, as an essential trace element, is crucial for various biological processes but has also been utilized as a constituent of various pesticides for decades. Copper (II) octanoate is a pesticide utilized as a fungicide and is approved for use in the production of certified organic foods. Previous studies have implicated copper as an inducer of oxidative stress and activator of the Nrf2-ARE pathway. Nrf2 is essential in regulating the transcription of various genes to alleviate toxicity such as those involved in glutathione synthesis and detoxification. Due to the limited toxicological data, this study into the potential induction of oxidative …

Growth And Survival Of Amphibians Exposed To Road Salt And Glyphosate-Based Herbicide, Jerica Eaton

Mahurin Honors College Capstone Experience/Thesis Projects

Amphibian populations are threatened by increasing levels of environmental pollution resulting from human activities. Areas with mixed land use that include agriculture and urban development experience increased contamination from surface herbicide and road deicer application. Upon entering water sources, these chemicals have the capacity to disrupt the natural dynamics of aquatic ecosystems. This study aimed to evaluate the effects of these contaminants on amphibian populations. I used the spotted salamander (Ambystoma maculatum) as a model, rearing larvae from hatching to metamorphosis. I subjected larvae in each of the treatment groups to varying levels of herbicide and salt concentrations. …

Trends In Cyanotoxin Production Potential In China Lake: An Edna Analysis Of Microcystis And Dolichospermum And The Environmental Drivers Of Cyanotoxin Production, Gennifer M. Rubin

Honors Theses

Episodes of cyano-harmful algal blooms (cyano-HABs) are hypothesized to be exacerbated by the effects of climate change. However, the dynamics of the interactions between elements of climate change and toxigenic cyanobacteria proliferation are not well defined. China Lake is the drinking water source for 7 municipalities in the Kennebec County and is one of many lakes in central Maine that has been subjected to high levels of cyano-HABs and microcystin toxin contamination in recent years. Monitoring the toxicity of these blooms in relation to various aspects of climate change may lead to identification of the major drivers of microcystin production …

Telomeres: A Tool To Assess The Impacts Of Mining Contaminants On Riparian Songbirds, Lillian Krach, Bridger Creel, Megan Fylling, Zac Cheviron, Creagh Breuner

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Mining has left massive environmental and physical scars across the landscape. Aquatic and riparian landscapes in particular have been significantly impacted by traditional mining practices. Waste products left over from hard-rock mining leech heavy metals onto the landscape and these metals spread from headwater streams to major waterways (Lottermoser 2010). Heavy metals have been shown to cause physiological stress and challenges to organisms depending on the metal and the concentration (Baos et al. 2019, Boyd & Rajakaruna 2013). While some mining-impaired areas have undergone restoration efforts, is it enough? Typical restoration methods replace the contaminated floodplain, but not the riverbed …

Revisiting The 2018 Corsica Oil Spill - A Preliminary Case Study Of Ecosystem Recovery From Pahs In Yelkouan Shearwater (Puffinus Yelkouan), Makenna Mahrer

CMC Senior Theses

Polycyclic aromatic hydrocarbons (PAHs) are a specific class of persistent organic pollutants (POPs) heavily associated with crude oil, and pose genotoxic and physiological threats to marine life when released into the aquatic environment during a petroleum spill. This study seeks to understand the residual impacts of the 2018 Corsica oil spill on Puffinus yelkouan (Yelkouan Shearwater), a seabird endemic to the Mediterranean basin, using the species as a bioindicator for contamination in the region. Though classified by the IUCN Red List as ‘vulnerable,’ this species remains grossly understudied in present monitoring literature. This study made use of blood samples and …

Halogen Bonding Interactions Of Haloaromatic Endocrine Disruptors And The Potential For Inhibition Of Iodothyronine Deiodinases, Craig A. Bayse

Chemistry & Biochemistry Faculty Publications

Halogen bonding (XB) is a potential mechanism for the inhibition of the thyroid-activating/deactivating iodothyronine deiodinase family of selenoproteins through interactions with halogenated endocrine disrupting compounds (EDCs). Trends in XB interactions were examined using density functional theory for a series of polyhalogenated dibenzo-1,4-dioxins, biphenyls, and other EDCs with methylselenolate, a simple model of the Dio active site selenocysteine. The strengths of the interactions depend upon the halogen (Br>Cl), the degree of substitution, and the position of the acceptor. In terms of donor-acceptor energies, interactions at the meta position are often the strongest, suggesting a link to the topology of THs, …

Ultrahigh-Performance Liquid Chromatography–Tandem Mass Spectrometry Quantitation Of O-Cresol In Hydrolyzed Human Urine To Assess Toluene Exposure, Eric Langlois, Sébastien Gagné

Études primaires

Rationale

Toluene is a volatile organic compound used in domestic and industrial applications. The main routes of workplace exposure to toluene are inhalation and dermal contact. As toluene exposure can cause severe nervous system damage, its quantification is crucial to prevent occupational illness. Toluene is metabolized mainly as hippuric acid, S-benzylmercapturic acid and epoxides. These are rapidly converted to o-/p-cresol, which is then excreted in the urine as conjugated glucuronides and sulfates. o-Cresol and its conjugates can be chemically hydrolyzed to form free o-cresol, which can then serve as a urinary biomarker of toluene exposure. Current …

Bioaccumulation Of Polychlorinated Biphenyl Compounds And Mercury In A Mining Impacted Aquatic Ecosystem, Michelle Bollini

Dissertations, Master's Theses and Master's Reports

The Keweenaw area continues to be influenced by the century of copper mining that ended nearly 50 years ago. This project is focused on Torch Lake, an aquatic ecosystem that has been heavily impacted by mining waste disposal. The watershed has been impaired by mine discharge and tailings, smelter and smokestack plumes, and poor waste disposal practices. The lake is listed as a Great Lakes Area of Concern with beneficial use impairments of restrictions on fish consumption and a degraded benthic community. Polychlorinated biphenyl compounds (PCBs) and methylmercury (MeHg) are persistent, bioaccumulative, and toxic substances (PBTs). These contaminants pose threats …

Assessment Of Spilled Toxic Bait By Wild Pigs And Potential Risk To Non-Target Species, John C. Kinsey, Justin A. Foster, Nathan P. Snow, Jason D. Wishart, Linton D. Staples, Janis K. Bush, Kurt V. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Background

In 2018, a sodium nitrite (SN)-based toxic bait for invasive wild pigs (hereafter wild pigs; Sus scrofa), was evaluated to determine its effectiveness in reducing local wild pig populations in Texas. Localized population reductions of > 70% were achieved, but spillage of bait outside wild pig-specific feeders (bait stations) caused by feeding wild pigs resulted in the deaths of non-target animals. To evaluate risks to non-target animals, we tested whether bait presentation influenced the total amount of bait spilled by wild pigs and estimated the associated risk to non-target species.

Results

We found that bait spilled outside bait stations …

Co-Occurrence Of Marine And Freshwater Phycotoxins In Oysters, And Analysis Of Possible Predictors For Management, Sarah K. D. Pease, Todd A. Egerton, Kimberly S. Reece, Marta P. Sanderson, Michelle D. Onofrio, Evan Yeargan, Adam Wood, Amanda Roach, I-Shuo Wade Huang, Gail P. Scott, Allen R. Place, Amy M. Hayes, Juliette L. Smith

Biological Sciences Faculty Publications

Oysters (Crassostrea virginica) were screened for 12 phycotoxins over two years in nearshore waters to collect baseline phycotoxin data and to determine prevalence of phycotoxin co-occurrence in the commercially and ecologically-relevant species. Trace to low concentrations of azaspiracid-1 and -2 (AZA1, AZA2), domoic acid (DA), okadaic acid (OA), and dinophysistoxin-1 (DTX1) were detected, orders of magnitude below seafood safety action levels. Microcystins (MCs), MC-RR and MC-YR, were also found in oysters (maximum: 7.12 μg MC-RR/kg shellfish meat wet weight), warranting consideration of developing action levels for freshwater phycotoxins in marine shellfish. Oysters contained phycotoxins that impair shellfish health: karlotoxin1-1 and …

Characterizing The Effects Of Antiandrogens And Senolytics To Enhance The Therapeutic Response To Castration-Resistant Prostate Cancer, Justin M. Silverman

Theses and Dissertations

Prostate cancer is the most frequently diagnosed cancer in males and the second most common cause of cancer deaths. Androgen deprivation therapy, whether through surgical or chemical castration, is the mainstay for treatment of advanced prostate cancer; however, despite an initial response, most patients eventually develop a progressive PSA rise, and castration- sensitive prostate cancer gives rise to castration-resistant prostate cancer. The standard of care therapy includes the antiandrogens such as enzalutamide and abiraterone acetate as well as the microtubule poison, docetaxel, and various immunotherapies; however, while prostate cancer research is progressing, there continues to be a compelling need for …

Promoting Healthier Treatment Outcomes In Obese Cancer Patients Taking High Dose Methotrexate, Carly Dell'ova

Walden Dissertations and Doctoral Studies

Cancer and obesity rates continue to rise, creating enormous public heath burdens to the individual and at the national and global levels, reducing quality of life, and increasing spending. Moreover, the relationships between cancer and obesity are not well understood. A commonly used chemotherapy for several types of cancer is high dose methotrexate (HDMTX). Along with chemotherapy, especially at high doses, comes toxicity to specific organs and the entire body. However, limited research has been conducted on obese cancer patients as they are often excluded from clinical studies. Practitioners need to better understand how to dose these patients to provide …

Acute Copper (Cu) Toxicity In Dragonfly Naiads (Insecta: Odonata), Jeff M. Simpson

Department of Entomology: Distance Master of Science Projects

The objective of this study was to examine the effects copper (Cu) on mortality within a pair of test groups of naiads in the order Odonata, and to replicate previous observations regarding their potential uses as indicators for water quality. Few past studies have examined toxicity within relation to the odonates. It has been suggested that this order may contain valuable model organisms (Tollett et al., 2008). Very little focus has been given to odonates as bioindicators, with the few studies done being performed on species that would typically inhabit lentic environments (Trevino, 1999). Similarly, the test subjects for this …